Fargo-Moorhead Area Diversion Project

Transcription

Fargo-Moorhead Area Diversion Project
Fargo-Moorhead Area
Diversion Project
Aaron Snyder
USACE Planner and Project Manager, PMP Chief,
Project Management Branch
Mark Brodshaug
Cass County Joint Water Resource District, Chairman
Presentation to:
Joint North Dakota Water Convention and Irrigation Workshop
December 4, 2014
Presentation Outline
Flood History &
Project Need
Flood Insurance
Federally Authorized
Project
Project Operations
Mitigation Efforts
Funding &
MN DNR EIS Update
Questions
2
Flood History
&
Project Need
3
Red River Basin
Total Drainage Area:
45,000 square miles
North
Dakota
Fargo, Moorhead,
ND
MN
Minnesota
Q 100 year
= 34,700 cfs
South
Q 500 year
= 61,700 cfs
Dakota
4
Q max 2009 = 29,500 cfs
Water Everywhere
West of Hjemkomst Center
Moorhead, MN & Fargo, ND
Transportation Challenges
Interstate 29
Closed April 10. Reopened April 15, 2011.
Detour added = 22.8 miles
Red River of the North at Fargo, North Dakota
Maximum Daily Flow Rate (cubic-feet per second)
70,000
60,000
● Flood flow frequency and magnitude since
1900 shows transitions from dry to wetcycles.
50,000
● 16 flood have exceeded the "Major Flood
Stage" since 1900.
40,000
● 8 of the 16 "major" floods have occurred
since 2000 through 2014.
30,000
20,000
Approximate Major Flood Stage
10,000
0
Source: USGS river flow data from USGS Station 05054000
500-Year Flood Event
100-Year Flood Event
The 2009 flood is the
largest flood on record
and equates to a
50-Year Flood Event.
Greater than 100-Year Protection is
Needed
Bigger floods have already been experience in Minot
and Grand Forks, North Dakota
Several 1,000-year flood events have occurred
across the region in the last few years
Red River Basin Commission recommends 500-year
protection for large metro areas like FargoMoorhead
Only Winnipeg meets the RRBC guidelines for flood
protection for cities in the Red River Basin
8
Diversion Projects Have Proven
Success in the RRB
Diversion Project in Winnipeg in place since 1969
– Was recently expanded from 90-year flood protection to
700-year flood protection
Has operated more than 20 times since its
completion
The prevented $32 billion in flood damages
Sheyenne Diversion continues to succeed in West
Fargo, North Dakota
9
Flood Insurance
10
Ever Changing Floodplain Risk
 Pre-2015 FEMA Floodplain
 38.5 Feet River Gage (29,300 cfs)
 475 Impacted Structures
 19,700 Acres Impacted
 2015 FEMA Floodplain
 39.4 Feet River Gage (29,300 cfs)
 Approx. 2,300 Impacted Structures
 27,600 Acres Impacted
 Future USACE Floodplain
 41.1 River Gage (34,700 cfs)
 Approx. 19,400 Impacted Structures
 36,430 Acres Impacted
Flooding Without
The Diversion
Blue = Existing 100-year
Floodplain (USACE)
Flooding With
The Diversion
Blue = With Project 100-year
Floodplain (USACE)
Federally
Authorized Project
14
Federal Feasibility Study
Multiple Alternatives Considered
• Non-structural
• Levees/floodwalls
• Upper basin storage
• Retention/controlled field runoff
• Diversion channels
• Combinations
- Diversions and Levees
- Various levels considered
- 10,000 to 45,000 cfs capacity diversions
- Up to 1-percent chance levees
• Levees alone unable to achieve certifiable 1% risk reduction
15
Why Not Levees?
• 100-year certification not feasible
• 50-year level (2009 flood) - $900
million cost
• No high ground on North Dakota
side
• Once levees are exceeded, entire
community floods
• Not as robust/reliable as
diversion
• Levee projects also have impacts
16
Why Not Distributed
Storage/Retention?
The Diversion Authority supports the
development of distributed storage
The Diversion Authority has
committed $25 million to develop
upstream retention projects
Distributed storage cannot provide the
level of protection of the Diversion
(~7’ reduction of the 100-year flood
stage).
The staging area is the most effective
and efficient retention, which is
necessary to mitigate downstream
impacts.
17
Initial Diversion Plan’s Downstream
Impacts
• Impacts in excess of 2-feet
• Downstream impacts would have reached to Canada
• Impacts on an estimated 4,500 structures
downstream of project based on pre-feasibility study
information
• Downstream impacts have been nearly eliminated by
implementing the staging area; the most effective
and efficient upstream storage
18
FM Area Diversion
Project
Federally Authorized Project
1,600 ft wide Diversion Channel
in ND with 150,000 acre-feet of
Upstream Staging
Outlet near Georgetown, MN
Inlet north of Oxbow, ND
Provides 1-percent (100-year)
Risk Reduction
Extreme Events are FloodFightable
Diversion Project Receives Federal
Authorization
President Obama signed the
Water Resources Reform and
Development Act (WRRDA) in
June 2014
WRRDA authorized construction
to move forward on the FargoMoorhead Area Diversion Project.
WRRDA authorized $846 Million
in federal funds for the Project
Diversion was 1 of 26 water
projects authorized
20
Federally Authorized Project
Provides risk reduction:
to the greatest amount of infrastructure
for the greatest number of people
from multiple river systems
•
•
•
•
•
•
Red River
Wild Rice River
Sheyenne River
Maple River
Rush River
Lower Rush River
Harwood
21
Authorized Project Makes Sense
1 in 5 of all North Dakotans will benefit from flood risk
reduction
$14 Billion = Property Value Receiving Flood Risk Reduction
Benefits
$4.3 Billion = Wages in the F-M Metro Area
$10 Billion = Annual F-M Gross Domestic Product
$222 Million = Annual Income & Sales Taxes Generated for
North Dakota from F-M Metro
$90 Million = Annual Income & Sales Taxes Generated for
Minnesota from F-M Metro
*Data from the Greater Fargo-Moorhead EDC
Improvements to the Project
Reduced the impacted residential structures from 4,500 downstream to
just 150 upstream of the Project
Included a ring levee for Oxbow-Hickson-Bakke, which prevented a
community-wide buyout of 196 homes
Moved southern alignment of the Diversion north by one mile.
– Lessened residential structure impacts and impacts to Richland and
Wilkin counties to just a handful of residences
Added gates to the Diversion Inlet to allow more flow through town and to
better control and minimize upstream impacts.
– Diminished potential for summer flooding upstream and damaging
standing crops
Increased levee heights within Fargo-Moorhead
– Lowered the frequency of Diversion use to only operate in flood events
greater than a 10-year flood (35 feet at Fargo gage)
– Reduced size and duration of the Staging Area
Diversion Channel
Cross Section
Total Width = 1,600 feet
24
Typical County Bridge Aesthetics
Conceptual Maple River
Aqueduct Structure Illustration
In-Town Levees
Key Aspect of Diversion Project
Over 700 home buyouts
metro-wide to date
35 foot Mitigation Measures
•
•
•
•
•
•
Existing Levee Certification (5)
El Zagal Area Protection
Mickelson Area Protection
2nd St./Downtown Protection
Belmont Area Protection
Individual Property
Mitigation/Acquisitions
• Transportation mitigation
measures (rural).
Diversion
Project
Operations
28
10-Year Flood Operation
No Project Operation
Under 10-Year Flood
Event
10-Year Flood Event = 35’
at Fargo Gage
Project would not have
operated during a
historic summer events
(1975, 2005, 2007, 2009)
29
Staging (“Retention”) Area
(100-year Event)
Defined area
Ability to mitigate for
impacts
Impacts to approximately 60
residences, with ring levees
around Oxbow-BakkeHickson and Comstock
Virtually eliminated all
downstream impacts
30
Mitigation
Efforts
31
Ongoing Mitigation Efforts
Residential Mitigation
– Residence and Farmstead Mitigation
• Impacts on residences and farmsteads >1’ require federal
mitigation (approximately 80 homes)
• Additional mitigation <1’ on a case by case basis
– Hardship Acquisitions
• 6 homes have been purchased at the request of their owners due
to hardships (2 additional have been approved for acquisition)
– Early Acquisitions
• Several farmland owners have approached the Diversion Authority
with an interest in selling their land
• The Diversion Authority has purchased 2,000 acres of farmland
from willing sellers who approached the Diversion Authority
32
Ongoing Mitigation Efforts
Cemetery Mitigation
– Corps of Engineers has released a 185-page report
detailing the cemeteries in the region, their current
flood threats, and what impacts may be from the
Diversion Project along with potential mitigation
options.
Agricultural Mitigation
– Flowage Easements
• A flowage easement is a one-time payment made to provide
the legal ability to inundate property as part of the operation
of the Project
– Replacement Income (Crop Insurance)
• NDSU’s Agribusiness Department has been contracted to
develop a plan to mitigate the impact on farmland
33
OHB Ring Levee
Construction began in
June, 2014
Provides 196 properties
with 500-year flood
protection
Removes real estate
“limbo” status for
residents
Protects the tax base of
the Kindred School
District
34
OHB Ring Levee Project (Sept 26, 2014)
REPLACEMENT LOTS
AND DEVELOPMENT
RING LEVEE
35
Funding &
MN DNR EIS
Update
36
Current Funding Philosophy
Total Project Costs
Federal : 45%
(capped at $800M)
Non-Federal: 55%
(balance of Project Costs)
North Dakota: 90%
State: 50%
37
Local: 50%
Minnesota: 10%
Funding Update
Local Funding
Voters have approved two dedicated sales tax measures for
the Diversion
Sales tax projections estimate collections
to total $700 Million over the life of the taxes
ND State Funding
State legislature has appropriated $175M with
legislative intent to give another $275M
Federal Funding
38
Authorization set the stage for this
effort to begin
Minnesota Environmental Impact State
& Funding Update
The DNR must produce an Environmental Impact Statement (EIS)
for the Project as required by Minnesota law
– EIS started February 20, 2014
– Draft EIS publication estimated April 2015
EIS examining five (5) Alternatives, including the Federal Project
and Two No Action Alternatives
Intent for Minnesota to cover 10% of all non-federal Project costs,
roughly 5.5% of total Project costs
Minnesota cost share could be requested from the MN Legislature
during the 2016 legislative session at the earliest
39
www.fmdiversion.com
40
www.fmdiversion.com
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